Patent GB-1239618-A (GB)
IPC: G09B7/08
Filed: 1968-10-15
Abstract: 1,239,618. Teaching machines. STRUCTURAL COMMUNICATION SYSTEMS Ltd. 1 Dec., 1969 [15 Oct., 1968], No. 48939/68. Headings G4M and G5G. A teaching machine comprises a card, Fig. 2, bearing two data fields. One field, odd columns 3-29 as shown, is prescored and is perforated by the student to indicate his response to a question posed in the teaching manual. The second field is punched with control data which determines whether or not the student's response is sufficiently correct and directs him accordingly to a part of the manual giving him further information, e.g. to remedy any faults in his knowledge. The response field accommodates six attempts at answering a question in sub-fields A1-A6. When the card has been perforated according to an attempt it is inserted in a reader, Fig. 6 (not shown), having two spring contact-bearing carriages. One carriage (122) is positioned over the relevant sub-field by manually rotating a click-stop thumbwheel (105) driving the carriage through a rack and pinion. The other carriage (126) also carries spring contacts and is driven across the control field by a rack and pinion, the pinion (138) being rotated by a helical spring (146) tensioned and released by a handle (114) operated by the student. At each scan of the control field seven tests, defined by rows 1-7, are performed on the data in the response subfield. As a row is scanned binary-weighted resistors are connected across one arm of a bridge in the control circuitry, the resistors being defined by data in columns 71-74. A resistor is connected in parallel with the opposed arm for each hole in columns 43-67 of the control field that has a corresponding hole punched in the response subfield by the student. The binary-weighted resistors connected to the bridge act as a reference value against which the student's response is judged. Data in columns 75-78 off-set the bridge balance in one or other direction according to whether the test performed on the response is one in which the student is required to have included certain elements in his answer, or not to have included certain elements. The bridge output indicates whether the student's response passes or fails the particular test. If a test is failed the circuitry takes no account of failure in subsequent ones of the tests (rows 2-7) performed on the present sub-field during scan of the control field. In the event of failure binary data read from columns 37-40 and decimal data from columns 41, 42 specify an address in the instruction manual by actuating a visual indicator. At this address the manual gives the student further information, which may enable him to present a correct response sub-field at a second attempt. The information may give alternative reasons for failure and suggest that the student should perforate the Y and/or Z elements in the orignal sub-field whereby he will be provided with further information. The manual may require the X element to be perforated if the responses gives by the student indicate that, for example, the student should be assessed less strictly. If all seven tests are passed the address of the next question or other information is given by data in row 8. Data in row 9 performs a circuit check. The response and control data fields may be on separate cards, and the control data field may be on a paper tape.